K45X50X27 bearing: complete specifications & equivalents
The K45X50X27 is a DIN 5402 radial bearing sized 45 x 50 x 27 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 45 mm |
| Outer diameter D | 50 mm |
| Width B | 27 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 33 kN |
| Basic static load rating C0 | 81.5 kN |
| Fatigue load limit Pu | 10 kN |
| Reference speed (thermal) | 9000 rpm |
| Limiting speed (mechanical) | 10000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 52 g |
| Manufacturer designation | K 45x50x27 |
| Standard | DIN 5402 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & K-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 1.969 in |
| Width B | 1.063 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 2.5 mm |
| Smallest bore in K-series | 3 mm |
| Largest outer diameter in K-series | 63 mm |
| Width range across K-series | 7–32 mm |
| Bore position in K-series (smallest first) | 19 of 22 |
| Bore above smallest K-series size | 42 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the K45X50X27 model number is decoded
SKF lists K 45x50x27 in the K series of needle roller and cage assemblies: needle rollers caged at 45×50×27 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. In the K code K 45x50x27, Fw×E×B reads directly as journal 45 mm, complement diameter 50 mm and cage width 27 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. Selection arithmetic: C 33 kN against C0 81.5 kN gives a C0/C ratio of 2.47, and the 10 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.
Typical equipment & failure modes
Common applications
- connecting rods of small compressors where radial height is critical
- rocker arm and rocker pin pivots on camshafts
- pump and gearbox idler gears running on hardened pins
- hinge and pivot joints in printing and textile machinery
Known failure patterns
- raceway spalling once the catalogue L10 life is exceeded or after overload events
- cage pocket wear and roller skew after sustained operation with too little radial preload
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- false brinelling of standby equipment under external vibration
- rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away
Selection pitfalls — read before you substitute
- At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.
- Hardness is load capacity: in families without an inner ring the 45 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.
- The quoted 33/81.5 kN ratings are SKF catalogue values for this exact execution (K 45x50x27); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- The 33/81.5 kN ratings and 52 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
How is the K 45x50x27 designation read?
K = needle roller and cage assembly (DIN 5402); the three figures give Fw 45 mm (shaft journal), E 50 mm (complement outside diameter, matched by the housing bore) and B 27 mm width. TN marks the glass fibre reinforced PA66 cage.
Can the K 45x50x27 run on an unhardened shaft?
No. In this execution the 45 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead.
How should the K 45x50x27 be mounted?
Slide the assembly over the ground 45 mm journal with a mounting sleeve, bore the housing to E 50 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded.
What limits the service life of a K 45x50x27?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 45 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.5 mm radial section leaves no reserve once a raceway is dented or ribboned.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies on 2026-09-26. Read our editorial & correction policy.